This invention relates to laminate type evaporators for use in air conditioning systems, and more particularly to improvements in or to refrigerant inlet and output pipes of an evaporator of this kind and fitting means therefor.
A laminate type evaporator for air conditioning systems for automotive vehicles generally has a laminated or superposed structure comprising a plurality of flat hollow bodies each composed of two stamped plates, each of which has opposite end tank-forming portions and an intermediate passage-forming portion, the two stamped plates being joined together in an abutting manner, wherein the tank-forming portions of the joined plates define tanks at opposite ends, and the passage-forming portions an intermediate passage, respectively, a plurality of fins, typically corrugated, the hollow bodies and the fins being superposed one upon another in an alternate manner, and a pair of end plates attached to outermost ones of the hollow bodies on the opposite sides.
To manufacture such evaporator, a semi-built-up assembly of component parts, held together by a suitable jig is charged into a furnace, and heated therein, whereby a brazing material previously applied or clad over the stamped plates and the corrugated fins is melt to unite the component parts together.
On this occasion, a refrigerant inlet pipe and a refrigerant outlet pipe, which are interposed between the tanks and one of the end plates, are also united with the other components by brazing in the furnace. Conventionally, such inlet and outlet pipes are formed of cold forged pipes having rectangular cross sections, and therefore have the following disadvantages:
(1) First, since they are manufactured by cold forging, they are rather expensive;
(2) They show a low yield in the furnace brazing;
(3) The stamped plates and the end plate, arranged at the opposite sides of the inlet and outlet pipes which are cold forged, are required to have rigidity sufficient to retain the pipes in place. Therefore, they need to have increased thicknesses, resulting in increased production costs.
(4) The inlet and outlet pipes are difficult to locate in place, providing a problem of dislocation from their proper places during their manufacture.